Just like a bath bomb. Toss in as many or as few as you would like. Maybe even a red and blue to make purple or yellow and blue to make green.
Get approx. 30 Fragrance free water-colouring tablets. Non-toxic, Unscented, Detergent free, Preservative free.
Ingredients: Sodium Bicarbonate, Citric Acid, Olea Europaea (Olive) Oil, Aqua,*Blue 1 Lake, *Red 40 Lake, *Yellow 5 Lake, *Yellow 6 Lake, *may contain
Directions: Place in full bath tub and watch dissolve.
Warning: Discontinue use if irritation occurs. Keep Product out of eyes. If product gets in eyes wish for sudden death or rinse with water.